(a) The provisions of 5 U.S.C. 556 and 557 , which govern formal hearings in adjudicatory proceedings, do not apply to informal rule making proceedings described in this part. When opportunity is afforded for oral presentation, such informal hearing is a nonadversary, fact-finding proceeding. Any rule issued in a proceeding under this part in which a hearing is held is not based exclusively on the record of such hearing.(b) When a hearing is provided, the Secretary will designate a representative to conduct the hearing, and if the presence of a legal officer is desirable, the General Counsel will designate a staff attorney to serve as the officer.